Photographing arrangement for use with a cathode-ray tube

ABSTRACT

A method and arrangement for photographing optical images such as oscillographic waveforms displayed on a faceplate of a cathode-ray tube, wherein a glass fiber screen is attached to the faceplate to form a display surface at the leading end of the glass fiber screen and a sensitized photographic film is placed directly upon the display surface of the glass fiber screen so that the images on the display surface are photographed on the film without use of a lens or lenses interposed between the film and the faceplate. The contact pressure between the film and the display surface is in operation maintained at a desired constant value through detection and conversion into electrical signals of the contact pressure for direct reading of the contact pressure.

United States Patent Morita et al.

[54] PHOTOGRAPHING ARRANGEMENT FOR USE WITH A CATHODE-RAY TUBE I [72]Inventors: Yasuyuki Morita; Tsutomu Nishino,

both of Kadoma, Japan [73] Assignee: Matsushita Electric IndustrialCompany, Limited, Kado ma, Osaka, Japan [22 Filed: Sept. 4, 1970 21Appl. No.: 69,648

[30] ForeignApplication Priority Data 2,455,206 11/1948 Wienke ..352/227Oct. 24, 1972 OTHER PUBLICATIONS Page-Width Fiber-Optic CRT Electronics,Vol. 34, N0. 34, Aug. 25, 1961; page 76 Primary Examiner-John M. HoranAssistant Examiner-Kenneth C. Hutchison l Attorney-McCarthy, Depaoli &O'Brien v[ 57] ABSTRACT A method and arrangement for photographingoptical images such as oscillographic waveforms displayed on a faceplateof a cathode-ray tube, wherein a glass fiber screen is attached to thefaceplate to form a display surface at the leading end of the glassfiber screen and a sensitized photographic film is placed directly uponthe display surface of the glass fiber screen so that the images on thedisplay surface are photographed on the film without use of a lens orlenses interposed between the film and the faceplate. The contactpressure between the film and the display surface is in operationmaintained at a desired constant value through detection and conversioninto electrical signals of the contact pressure for direct reading ofthe contact pressure. v

5 Claims, 3 Drawing Figures Patented Oct. 24, 1972 INVENTORS YAS U YUKIMOE/TA BY TSUTOMl/ N/SH/M %c ATT RN YS PHOTOGRAPIIING ARRANGEMENT FORUSE WITH A CATIIODE-RAY TUBE The present invention relates tophotographing and, more particularly, to a method and arrangement forphotographing optical images on a faceplate of cathode-ray tube.

In photographing optical images such as oscillographic waveformsdisplayed on a faceplate of a cathode-ray tube, it is presently a commonpractice to have the optical images focussed on a sensitizedphotographic film through a lens or lenses positioned between the filmand the faceplate. The use of such extra lens or lenses results in anincreased number of components and parts of the photographing device,which consequently is reflected by an increased production cost andrather complicated photographing operations when the photographingdevice is put on practical use. What is more important, the resolutionof the resultant images photographed on the photographic film isnecessarily degraded where a lens or lenses are interposed between thefilm and the faceplate of the cathode-ray tube.

It is, therefore, and important object of the present invention toprovide an improved arrangement for photographing optical images on afaceplate of a cathode-ray tube, the arrangement being simple inconstruction and easy to manipulate.

It is another important object of the invention to provide aphotographing device which is capable of photographing an optical imageon a faceplate of a cathode-ray tube with a satisfactory resolution.

In order to achieve these and other objects, the invention contemplatesremoval of a lens or lenses which are conventionally interposed betweenthe photographic film and the faceplate of the cathode-ray tube.According to a first essential aspect of the present invention,therefore, a glass fiber screen is attached to the faceplate of thecathode-ray tube so as to form a display surface at the leading or outerend of the glass fiber screen and the sensitized photographic film isplaced directly on the display surface bearing the optical imagesthereon so that the optical images are photographed on the film withoutuse of an extra lens or lenses mounted in between. According 'to asecond essential aspect of the invention, the contact pressure betweenthe film and the display surface is in operation detected and convertedinto corresponding electric signals. The resultant electric signals areregistered on a contact pressure indicator for visual reading so thatthe photographic film is pressed upon the display surface at aconstantly regulated pressure.

Any type of cathode-ray tube may be utilized to put the presentinvention into practice where it is desired to photograph the opticalimages displayed on the faceplate of the cathode-ray tube.

In the method and arrangement for photographing optical images on thefaceplate of a cathode-ray tube, a glass fiber screen is attached to thefaceplate to form an image display surface at the leading or outer endof the screen. This is advantageous because the display surface can beprotruded from the surface of the faceplate of the cathode-ray tube,thus facilitating the photographic film to approach and contact thedisplay surface. Provision of the glass fiber screen with a displaysurface formed at its leading end is also beneficial for compensatingfor the curvature of the faceplate of the cathode-ray tube and forshaping the frame of the optical image as desired.

A sensitized photographic film, which is loaded in a suitablephotographing means, is placed apart from the display surface of theglass fiber screen through which the optical image on the faceplate ofthe cathode-ray tube is guided to and displayed on the display surface.The photographic film is then moved together with the photographic meanstoward the display surface until the former contacts the latter. Thephotographic film is thus pressed closely upon the display surface andthe pressure, at which the film is made to contact the display surface,is detected and converted into electric signals corresponding thereto.In this instance, the contact pressure between the film and the displaysurface may be modified for linearly continuous detection and convertionof the contact pressure into the electric signalssThe resultant electricsignals are visually registered on a contact pressure indicator forbeing read directly with human eyes, so that the contact pressurebetween the film and the display surface can be adjusted to andmaintained at a constant value. The image guided from the faceplate ofthe cathode-ray tube to the display surface of the glass fiber screen isin this manner photographed by manipulation of the photographing means.

The photographing means applicable to the method and arrangementaccording to the invention may be of any known type but, preferably, themeans may include a mechanism by which images can be photographed ondifferent positions of a single photographic film.

The arrangement to carry out the above described method is shown in theaccompanying drawings, in which:

FIG. 1 is an exploded view of an arrangement according to the invention;

FIG. 2 is a sectional view of a pressure detecting means used in thearrangement of FIG. 1, the detecting means being shown as keptinoperative; and

FIG. 3 is similar to FIG. 2, but the pressure detecting means is hereinshown as being operative.

Referring to the drawings, particularly to FIG. 1, the photographingarrangement according to the invention is shown as used in combinationwith a measuring instrument l0 and a photographing means or cameraassembly which is generally represented by reference numeral 11. Themeasuring instrument 10, used for the measurement and registration ofvarying electric and other characteristics or phenomena, includes acathode-ray tube, not shown, which is accommodated therein for visualobservation of such varying characteristics or phenomena at itsfaceplate, not shown.

A glass fiber screen 12 is attached to the faceplate of the cathode-raytube, forming at its leading end an image display surface 12a ofselected configuration and size.

The photographing means or camera assembly 11 is essentially made up ofa camera frame structure 13, a slide frame 14 engageable with the cameraframe structure 13, a camera pack frame structure 15, a shutter panel 16engageable with the camera pack from structure l5 and a camera pack body17 loaded with a photographic film. The structures and members 13 to 17are all held together as will be discussed in more detail.

The camera frame structure 13 has formed therein an opening 18 which isshaped and sized to receive therein the slide frame 14 throughengagement of recesses 19a, 19b, 19c and 19d formed on the framestructure 13 with claws 20a, 20b, 20c and 20d, respectively, formed onthe slide frame 14, wherein the claw 20d is shown as concealed behindthe frame 14 and hence not identified. A stop member 21 may be mountedon the frame structure 13 for stepwisely moving the slide frame 14 whichis held in engagement with the frame structure 13. The camera framestructure 13 is. also provided with a stop member 22 and pivotal shafts23 and 23' secured to the frame structure 13 for the reason hereinafterdiscussed.

The slide from frame 14 and the camera pack frame structure 15 haveformed therein openings 24 and 25, respectively, which are shaped andsized in alignment with each other. Designated by reference numeral 26is a light-interceptive felt member mounted on the camera pack framestructure 15. The camera pack frame structure 15 has formed on one sidethereof a depression 27 which is adapted for engagement with the shutterpanel. 16. The shutter panel 16 has a bent portion 28 formed at itsupper edge and a stop member 29 mounted at its lower edge, asillustrated. The camera pack body 17 has loaded therein a sensitizedphotographic film 30 which can be drawn out thereof through an elongatedslot 31. The slide frame 14 and the camera pack frame structure 15,engaging with each other through the shutter panel 16 received in thedepression 27 in the latter, are accommodated in the camera pack body 17and are mounted on the camera frame structure 13 through engagement ofthe recesses 19a to 19d of the frame structure 13 with the claws 20a to20d of the slide frame 14.

Now, according to the invention means is provided to move the thusconstructed photographing means or camera assembly 11 toward and awayfrom the display surface 12a of the glass fiber screen 12 attached tothe cathode-ray tube. The means for moving the camera 1 1 includes amain guide spindle 32 and auxiliary guide spindles 33 and 33', all ofwhich are mounted in parallel to each other on a support structure 34which is fixed relative to the cathode-ray tube to the wall of themeasuring instrument 10 through fastening means 35a, 35b, 35c and 35d.It is preferable that guide spindles 32, 33 and 33 be mounted at a lowerportion of the support structure 34 so as to provide a ready access to aspace between a camera frame support member 36 and the support structure34. The auxiliary guide spindles 33 and 33' are herein shown as two innumber but the same may be provided in any desired number. The mainguide spindle 32 is provided with a rack 32a.

The camera frame support member 36 included in the camera moving meanshas formed therein an opening 37 which is shaped, sized and positionedin alignment with the display surface 12a and with the openings 24 and25 in the slide frame 14 and the camera pack frame structure 15,respectively. On the camera frame support member 36 is mounted a bossmember 38 which is internally hollowed to form an axial bore 38a throughwhich the main guide spindle 32 is slidably inserted. The boss member 38is provided with a slide adjustment pin 39 having a pinion (not shown)meshing with the rack 32a of the main guide spindle 32 and a slide stoppin 40 for tightening the slide adjustment pin 39. The camera framesupport member 36 has also formed therein guide holes 41 and 41' throughwhich the auxiliary guide spindles 33 and 33', respectively, areslidably inserted. Bearings 42 and 42 are mounted on one of the sideedges of the camera frame support member 36, so that the camera framestructure 13 is detachably and hingedly mounted on the camera framesupport member 36 through pivotal engagement of the shafts 23 and 23with the bearings 42 and 42', respectively. A slot 43 is formed on theside edge of the frame support member 36 opposite to the side edge onwhich the bearing 42 and 42' are mounted, which slot 43 is engageablewith the stop member 22 when the camera frame structure 13 is mounted onthe camera frame support member 36, as will be mentioned later.

Means 44 is further provided so as to optically seal the space betweenthe support structure 34 and the camera frame support member 36, whichmeans comprises a bellows 45 secured at both ends to supports 46 and 46through which the sealing means 44 is mounted on the camera framesupport member 36 and the support structure 34, respectively.

The slide frame 14 and the camera pack frame structure 15 engaging withthe slide frame 14 through the shutter panel 16 are accommodated in thecamera pack body 17, all of which are mounted on the camera framestructure 13 through the recesses 19a to 19d to thereby form thephotographing means or camera assembly 11. The vertical positions of theslide frame 14, camera pack frame structure 15, shutter panel 16 andcamera pack body 17, all held together, are held in place and movedstepwisely downwardly by manipulating the stop member 21, so that aplurality of different images can be photographed on different positionsof one and the same photographic film 30.

The photographing means or camera assembly 11 is mounted as a whole onthe camera frame support member 36 hingedly through the pivotalshafts 23and 23 and the bearings 42 and 42, and is secured thereto throughengagement of the stop member 22 with the slot 43. The resultantassembly of the photographing means or camera assembly 11 and the framestructure 36 are moved toward and away from the display surface 12a byrotating the slide adjustment pin 39 which is connected to the pinionmeshing with the rack 32a, so that the photographing film 30 can bebrought into contact with the display surface 12a when the assembly ofthe photographing means or camera assembly 11 and the camera framesupport member 36 is moved to a position closest to the supportstructure 34 on the measuring instrument 10.

Turning now to FIG. 2, means is provided for detecting the pressure atwhich the photographic film 30 is held in contact with the displaysurface 12a, which means includes a pressure modifier means 47 mountedon the camera frame support member 36. The pressure modifier means 47includes an open-ended outer casing 48, an inner casing 49 which isclosed at its leading end and which is slidably inserted into the outercasing 48, and a compression spring 50 accommodated in and between theouter and inner casings 48 and 49, respectively. The inner casing 49 isthus biased forwardly by the action of the compression spring 50. Thepressure detecting means further includes a pressure sensitive element51 which is secured to the support structure 34 and which is positionedin alignment with the pressure modifier means 47. The inner casing 49which is normally held in a protruded position by the action of thespring 50, contacts the pressure sensitive element 51 as the cameraframe support member 36 approaches the support structure 34, asindicated by phantom lines in FIG. 2. As the frame support member 36 isfurther advanced toward the support structure 34 with the slideadjustment pin 39 rotated so that the photographic film 30 is pressedagainst the display surface 12a with an increasing pressure, the innercasing 49, pressing upon the pressure sensitive element 51, is graduallyretracted into the outer casing 48 against the action of the spring 50,as seen in FIG. 3. The variation in the contact pressure between thephotographic film 30 and the display surface 12a is in this mannerdetected from time to time by the pressure sensitive element 51.

The pressure sensitive element 51 is connected to means for convertingthe contact pressure, applied to the pressure sensitive element 51, intocorresponding electric signals, which are registered visually on acontact pressure indicator 52 which may be mounted on the measuringinstrument 10, as illustrated in FIG. 1.

1f, now, the spring constant of the compression spring 50 is k, then theforce F which the pressure sensitive element 51 receives from thepressure modifier means 47 will be expressed as F kx, where x is abetween the free length and a compressed length of the spring 50. Thus,a force proportional to the amount of displacement of the camera framesupport member 36 is imparted to the pressure sensitive element 51. Thismeans that, if the pressure applied to the pressure sensitive element isknown, then not only the position of the camera frame support member 36relative to the support structure 34 can be properly adjusted but thecontact pressure between the display surface 12a of the glass fiberscreen and the photographic film 30, which is constantly pressed towardthe display surface 12a by a spring mounted behind the film in thecamera pack body 17, can be properly adjusted.

When the inner casing 49 is pressed upon the pressure sensitive element51 and fully retracted into the outer casing 48 against the action ofthe spring 50, then the pressure applied to the pressure sensitiveelement 51 is kept constant because, in this instance, the pressuresensitive element 51 is subjected only to the pressure exerted by thecompression spring 50 with the outer casing 48 held in abutment to thesupport structure 34. The pressure modifier 47 thus acts not only tocarry a modified pressure to the pressure sensitive element 51 but toprotect the element 51 from being subjected to an excess pressure withthe outer casing 48 serving as a stop member.

When, now, in photographing an optical image displayed on the displaysurface 12a of the glass fiber screen 12, the camera frame structure 13,complete with the slide frame 14, camera pack frame structure 15,shutter panel 16 and camera pack body 17, should be mounted on thecamera frame support member 36 through pivotal connection of the shafts23 and 23' with the respective bearings 42 and 42. The camera framestructure 13 is secured to the camera frame support member 36 byengaging the stop member 22 with the slot 43. The shutter panel 16should then be pulled upwardly. The slide stop pin 40 is loosened andthe slide adjustment pin 39 is rotated to move the camera frame supportmember 36 with the camera assembly 1 1 toward the support structure 34,until it is known from reading of the indicator 52 that the photographicfilm 30 in the camera pack body 17 is brought into contact with thedisplay surface 12a. The contact pressure between the film 30 and thedisplay surface 120 can be adjusted properly by rotating the slideadjustment pin 39. When adjustment of the contact pressure is complete,then the slide stop pin 40 should be rotated to tighten the slideadjustment pin 39, thereby maintaining the film 30 in contact with thedisplay surface 12a with a selected pressure. The camera assembly 11 isnow in condition for photographing the image borne on the displaysurface 12a. In order to photograph an optical image on the displaysurface 12a for a second time on the same film 30, the stop member 22should be lowered a step so that the camera pack body 17 in its entiretyis accordingly lowered a step, whereby the image on the display surface12a can be photographed on a different position on the same film 30.When the photographing operation is complete, the slide stop pin 40should be loosened and the slide adjustment pin 39 rotated until thecamera frame support member 36, together with the camera assembly 11, ismoved to a position farthest from the support structure 34. Then, theshutter panel 16 should be lowered and the film 30 drawn out of thecamera pack body 17 for development and printing.

Where is is desired to visually observe the image on the display surface12a, the stop member 22 of the camera frame structure 13 should bedisengaged from the slot 43 in the camera frame'support member 36 sothat the frame structure 13 can be rotated about the shafts 23 and 23away from the support member 36. The display surface 12a of the glassfiber screen 12 can then be readily viewed with human eyes through theopening 37 in the camera frame support member 36.

It will now be apparent from the foregoing description that thephotographing arrangement according to the invention is advantageous inthat:

a. no sizing means such as a graduated scale need be used because theimage on the display surface is photographed on the film in the samesize;

b. the images can be photographed on different positions of the samephotographic film, providing increased economy and efficiency inphotographing operations;

c. the image on the display surface can be visually observed withoutneed of removing the camera assembly from the sliding mechanismincluding the camera frame support member;

d. the space between the support structure and the camera frame supportmember is readily accessible because the guide spindles are mounted onthe lower portion of the support structure;

e. the camera assembly can be moved back and forth easily and simply bymeans of a combination rack and pinion mechanism;

f. the camera assembly can be easily assembled and disassembled whilethe assembly as a whole can be readily attached to and detached from thecamera frame support member; and

g. the contact pressure between the film and the display surface can bedirectly read on the contact pressure indicator and adjusted properlyfrom time to time.

What is claimed is:

l. A combination, with a-cathode-ray tube having a faceplate on which anoptical image is produced and a photographing means which is loaded witha sensitized photographic film on which said optical image is to bephotographed, of a glass fiber screen which is attached to saidfaceplate and which has formed at its leading end an image displaysurface, moving means for moving said photographing means toward andaway from said display surface, detecting means for detecting a contactpressure between said film and said display surface when the film andthe display surface are in contact with each other, converting means forconverting said contact pressure into electric signals correspondingthereto for adjustment of said contact pressure by said moving means,and sealing means for optically sealing a space between said cathode-raytube and said photographing means.

2. A combination according to claim 1, wherein said moving meansincludes a main guide spindle and auxiliary guide spindles mounted inparallel to each other on a support structure which is fixed relative tosaid cathode-ray tube, and a camera frame support member for detachablysupporting said photographing means, which camera frame support memberhas formed therein an opening shaped, sized and positioned in alignmentwith said display surface and with said photographing means and includesa hollowed boss member which is positioned in alignment with said mainguide spindle and through which the main guide spindle is slidablyinserted, guide holes which are located in alignment with said auxiliaryguide spindles,

and slide adjusting means for sliding said camera frame support membertogether with said photographing means on said main and auxiliary guidespindles through said boss member and said guide holes.

3. A combination according to claim 2, wherein said slide adjustingmeans includes a rack member provided on said main guide spindle, apinion mounted on said boss member and meshing with said rack member, aslide adjustment pin mounted on said boss member and operativelyconnected to said pinion for rotating the pinion on said rack member tocause said camera frame support member to slide on said main andauxiliary guide spindles, and a slide stop pin mounted on said bossmember for tightening said slide adjustment pin to have said cameraframe support member properly positioned relative to said supportstructure.

4. A combination according to claim 2, wherein said main and auxiliaryguide spindles are mounted on a lower part of said support structure.

5. A combination according to claim 1, wherein said detecting meanscomprises a pressure modifier means including an open-ended outer casingfixedly mounted on said camera frame support structure, an inner casingwhich is closed at its outer end and opened at its inner end and whichis slidably inserted into said outer casing and a compression springaccommodated in and between said outer and inner casings, and a pressuresensitive element which is mounted on said support structure inalignment with said modifier means and which is sensitive to pressurecarried thereto from said inner casing when the inner casing is incontact with the pressure sensitive element, whereby the contactpressure between said photographing film and said display surface whichare in contact with each other is detected.

1. A combination, with a cathode-ray tube having a faceplate on which anoptical image is produced and a photographing means which is loaded witha sensitized photographic film on which said optical image is to bephotographed, of a glass fiber screen which is attached to saidfaceplate and which has formed at its leading end an image displaysurface, moving means for moving said photographing means toward andaway from said display surface, detecting means for detecting a contactpressure between said film and said display surface when the film andthe display surface are in contact with each other, converting means forconverting said contact pressure into electric signals correspondingthereto for adjustment of said contact pressure by said moving means,and sealing means for optically sealing a space between said cathode-raytube and said photographing means.
 2. A combination according to claim1, wherein said moving means includes a main guide spindle and auxiliaryguide spindles mounted in parallel to each other on a support structurewhich is fixed relative to said cathode-ray tube, and a camera framesupport member for detachably supporting said photographing means, whichcamera frame support member has formed therein an opening shaped, sizedand positioned in alignment with said display surface and with saidphotographing means and includes a hollowed boss member which ispositioned in alignment with said main guide spindle and through whichthe main guide spindle is slidably inserted, guide holes which arelocated in alignment with said auxiliary guide spindles, and slideadjusting means for sliding said camera frame support member togetherwith said photographing means on said main and auxiliary guide spindlesthrough said boss member and said guide holes.
 3. A combinationaccording to claim 2, wherein said slide adjusting means includes a rackmember provided on said main guide spindle, a pinion mounted on saidboss member and meshing with said rack member, a slide adjustment pinmounted on said boss member and operatively connected to said pinion forrotating the pinion on said rack membeR to cause said camera framesupport member to slide on said main and auxiliary guide spindles, and aslide stop pin mounted on said boss member for tightening said slideadjustment pin to have said camera frame support member properlypositioned relative to said support structure.
 4. A combinationaccording to claim 2, wherein said main and auxiliary guide spindles aremounted on a lower part of said support structure.
 5. A combinationaccording to claim 1, wherein said detecting means comprises a pressuremodifier means including an open-ended outer casing fixedly mounted onsaid camera frame support structure, an inner casing which is closed atits outer end and opened at its inner end and which is slidably insertedinto said outer casing and a compression spring accommodated in andbetween said outer and inner casings, and a pressure sensitive elementwhich is mounted on said support structure in alignment with saidmodifier means and which is sensitive to pressure carried thereto fromsaid inner casing when the inner casing is in contact with the pressuresensitive element, whereby the contact pressure between saidphotographing film and said display surface which are in contact witheach other is detected.